We show that algebraic proofs are hard to find: Given an unsatisfiable CNF formula F, it is NP-hard to find a refutation of F in the Nullstellensatz, Polynomial Calculus, or Sherali-Adams proof systems in time polynomial in the size of the shortest such refutation. Our work extends, and gives a simplified proof of, the recent breakthrough of Atserias and Müller (JACM 2020) that established an anal

The coexistence of Mott localized f states with wide conduction and valence bands in f-electron semiconductors results, quite generically, in a complex optical response with the nature of the absorption edge difficult to resolve both experimentally and theoretically. Here, we combine a dynamical mean-field theory approach to localized 4f shells with an improved description of band gaps by a semilo

Cooperative hunting involves individual predators relating in time and space to each other’s actions to more efficiently track down and catch prey. The evolution of advanced cognitive abilities and sociality in animals are strongly associated with cooperative hunting abilities as has been shown in lions, chimpanzees, and dolphins. Much less is known about cooperative hunting in seemingly unsocial

Aims: Previous studies on major depressive disorder (MDD) among immigrants have reported mixed results. Using data from primary healthcare settings in Sweden, we compared the incidence of MDD among first- and second-generation immigrants aged 15–39 years with natives. Methods: This was a retrospective nationwide open cohort study. Eligible individuals were born 1965–1983, aged 15–39 years at basel

Quantum dot based parity-to-charge conversion is a promising method for reading out quantum information encoded nonlocally into pairs of Majorana zero modes. To obtain a sizable parity-to-charge visibility, it is crucial to tune the relative phase of the tunnel couplings between the dot and the Majorana modes appropriately. However, in the presence of multiple quasidegenerate dot orbitals, it is i

The Ukrainian Shield and Voronezh Crystalline Massif constitute the Sarmatian segment of Baltica. Here, only a few mafic-ultramafic dykes and layered intrusions have been dated, recording early Statherian (ca. 1800–1750 Ma) ages. We have determined new U-Pb baddeleyite ages for the Novogol sill (1789 ± 2 Ma) and the Gremyachye intrusion (1781 ± 7 Ma), which fall within the previously established a

Objective: To determine the serotype distribution and antimicrobial resistance of Streptococcus pneumoniae associated with mucosal infections in patients of all ages, 2 to 4 years after the transition from a 10-valent pneumococcal conjugate vaccine (PCV10) to PCV13 in the childhood immunization programme. Methods: Background information and antimicrobial susceptibility data regarding all respirato

As a classical polymer acceptor material, N2200 has received extensive attention and research in the field of polymer solar cells (PSCs). However, the intrinsic properties of ground- and excited-states in N2200, which are critical for the application of N2200 in PSCs, remain poorly understood. In this work, the ground- and excited-state properties of N2200 solution and film were studied by steady-

An essential step for improving climate change models' performance is to evaluate their ability to represent the current climate conditions, especially extreme events. On such background, this study aims at evaluating the performance of the Quantile Delta Mapping (QDM) as a bias correction method for annual maximum daily precipitation series (bmax) generated from downscaled climate change models u

The solvation of alkali and halide ions in the aqueous environment has been a subject of intense experimental and theoretical research with multidisciplinary interests; yet, a comprehensive molecular-level understanding has still not been obtained. In recent years, electron spectroscopy has been increasingly applied to study the electronic and structural properties of aqueous ions with implication

A large contribution to glucose elimination from the circulation is achieved by insulin-independent processes. We have previously shown that the two incretin hormones, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) increase this process and, therefore, seem to contribute to glucose disposal both through this effect and through the classical incretin effect r

Screening for atrial fibrillation (AF) with a handheld device for recording the ECG is becoming increasingly popular. The poorer signal quality of such ECGs may lead to false detection of AF, often caused by transient noise. Consequently, the need for expert review in AF screening can become extensive. A convolutional neural network (CNN) is proposed for transient noise identification in AF detect

Slope stability is an important aspect in the management of civil engineering projects. The stability of earth slopes is a significant concern for safety and the economy. There are several methods for finding the safety factor. Spencer's method is considered one of the most accurate methods for calculating the factor of safety but it depends on the others on dividing the slope geometry into the nu

Social sustainability is the much emphasized organizational phenomenon in Western lit-erature; however, in emerging economies, its importance has only been realized in the recent past. Social sustainability is the amiability of the relationship between employees and the organizations on a relatively permanent basis. Social sustainability is the key determinant of organizational sus-tainability and

Internationally, mental health service developments are increasingly informed by the principles of recovery, and the availability of arts and creative activities are becoming more common as part of provision. Mental health service users’ experiences, reflecting on the complex nature of using music participation in recovery are, however, limited. This essay considers literature that explores how mu

All phase III trials evaluating medical treatments for traumatic brain injury (TBI), performed to date, have failed. To facilitate future success there is a need for novel outcome metrics that can bridge pre-clinical studies to clinical proof of concept trials. Our objective was to assess diffusion tensor imaging (DTI) and biofluid-based biomarkers as efficacy outcome metrics in a large animal stu

In cold region, conceptual models assigned precipitation phase, liquid (rain) or solid (snow), cause vastly different atmospheric, hydrological, and ecological responses, along with significant differences in evaporation, runoff, and infiltration fates for measured precipitation mass. A set air temperature threshold (ATT) applied to the over 30% annual precipitation events occurring with surface a

The National Institutes of Health hosted a workshop in 2019 to build consensus around the current state of understanding of the pathophysiology of postural orthostatic tachycardia syndrome (POTS) and to identify knowledge gaps that must be addressed to enhance clinical care of POTS patients through research. This second (of two) articles summarizes current knowledge gaps, and outlines the clinical

Background and objective Few studies have investigated the association between surgical volume and outcome of robot-assisted radical prostatectomy (RARP) in an unselected cohort. We sought to investigate the association between surgical volume with peri-operative and short-term outcomes in a nation-wide, population-based study group. Methods 9,810 RARP's registered in the National Prostate Cancer

Agricultural management practices and extreme weather events associated with climate change can influence the diversity and abundance of arbuscular mycorrhizal fungi (AMF) with potential consequences for crop production. However, the importance of the interactive effects of long-term agricultural management and extreme weather events on AMF communities in agricultural soils is not yet fully explor